<?php
	/**
	 * EasyPeasyICS Simple ICS/vCal data generator.
	 * @author Marcus Bointon <phpmailer@synchromedia.co.uk>
	 * @author Manuel Reinhard <manu@sprain.ch>
	 *
	 * Built with inspiration from
	 * http://stackoverflow.com/questions/1463480/how-can-i-use-php-to-dynamically-publish-an-ical-file-to-be-read-by-google-calend/1464355#1464355
	 * History:
	 * 2010/12/17 - Manuel Reinhard - when it all started
	 * 2014 PHPMailer project becomes maintainer
	 */

	/**
	 * Class EasyPeasyICS.
	 * Simple ICS data generator
	 * @package phpmailer
	 * @subpackage easypeasyics
	 */
	class EasyPeasyICS
	{
		/**
		 * The name of the calendar
		 * @type string
		 */
		protected $calendarName;
		/**
		 * The array of events to add to this calendar
		 * @type array
		 */
		protected $events = array();

		/**
		 * Constructor
		 * @param string $calendarName
		 */
		public function __construct($calendarName = "")
		{
			$this->calendarName = $calendarName;
		}

		/**
		 * Add an event to this calendar.
		 * @param string $start The start date and time as a unix timestamp
		 * @param string $end The end date and time as a unix timestamp
		 * @param string $summary A summary or title for the event
		 * @param string $description A description of the event
		 * @param string $url A URL for the event
		 * @param string $uid A unique identifier for the event - generated automatically if not provided
		 * @return array An array of event details, including any generated UID
		 */
		public function addEvent($start , $end , $summary = '' , $description = '' , $url = '' , $uid = '')
		{
			if (empty($uid)) {
				$uid = md5(uniqid(mt_rand() , true)) . '@EasyPeasyICS';
			}
			$event = array(
				'start'       => gmdate('Ymd' , $start) . 'T' . gmdate('His' , $start) . 'Z' ,
				'end'         => gmdate('Ymd' , $end) . 'T' . gmdate('His' , $end) . 'Z' ,
				'summary'     => $summary ,
				'description' => $description ,
				'url'         => $url ,
				'uid'         => $uid
			);
			$this->events[] = $event;
			return $event;
		}

		/**
		 * @return array Get the array of events.
		 */
		public function getEvents()
		{
			return $this->events;
		}

		/**
		 * Clear all events.
		 */
		public function clearEvents()
		{
			$this->events = array();
		}

		/**
		 * Get the name of the calendar.
		 * @return string
		 */
		public function getName()
		{
			return $this->calendarName;
		}

		/**
		 * Set the name of the calendar.
		 * @param $name
		 */
		public function setName($name)
		{
			$this->calendarName = $name;
		}

		/**
		 * Render and optionally output a vcal string.
		 * @param bool $output Whether to output the calendar data directly (the default).
		 * @return string The complete rendered vlal
		 */
		public function render($output = true)
		{
			//Add header
			$ics = 'BEGIN:VCALENDAR
METHOD:PUBLISH
VERSION:2.0
X-WR-CALNAME:' . $this->calendarName . '
PRODID:-//hacksw/handcal//NONSGML v1.0//EN';
			//Add events
			foreach ($this->events as $event) {
				$ics .= '
BEGIN:VEVENT
UID:' . $event['uid'] . '
DTSTAMP:' . gmdate('Ymd') . 'T' . gmdate('His') . 'Z
DTSTART:' . $event['start'] . '
DTEND:' . $event['end'] . '
SUMMARY:' . str_replace("\n" , "\\n" , $event['summary']) . '
DESCRIPTION:' . str_replace("\n" , "\\n" , $event['description']) . '
URL;VALUE=URI:' . $event['url'] . '
END:VEVENT';
			}
			//Add footer
			$ics .= '
END:VCALENDAR';
			if ($output) {
				//Output
				$filename = $this->calendarName;
				//Filename needs quoting if it contains spaces
				if (strpos($filename , ' ') !== false) {
					$filename = '"' . $filename . '"';
				}
				header('Content-type: text/calendar; charset=utf-8');
				header('Content-Disposition: inline; filename=' . $filename . '.ics');
				echo $ics;
			}
			return $ics;
		}
	}
